This study uses the grounded theory approach (GTA) to investigate the value and characteristics of teacher observations, when used to understand student learning. Earlier studies have analysed the act of observation, defining it as a combination of joint observation and interpretation activities. By contrast, this analysis of 28 primary school teachers in remote areas of Vietnam reveals that the act of observation is mediated by underlying values. This study develops a discussion about the way in which the inherent "compliance-with-a-plan" value restricts teachers' ability to develop knowledge, as proposed in the literature, while the value of 'exploration' encourages teachers to develop a broader interpretation of classroom interactions. Figures and tables illustrate these GTA-based results.